Study: Benzene byproducts found in pregnant women near fracking sites

A Montreal study of exposure to high levels of benzene during pregnancy raises concerns about the risks for childhood leukemia.

A team of Université de Montréal researchers looking at a small sample of 29 women living near major natural-gas well sites found high levels of toxins in their urine.

Researchers found they had 3.5 times more benzene byproducts in their urine than the average person in Canada. But in nearly half the participants, 14 of them Indigenous women, the levels were six times higher.

Contaminants, including volatile organic compounds, are released during hydraulic fracturing or fracking, and pregnancy is a vulnerable window of exposure for the mother and fetus, especially in the first months of pregnancy, said Élyse Caron-Beaudoin, a post-doctoral researcher at the Université de Montréal Public Health Research Institute and lead author. Results of the pilot study, led by toxicology risk-assessment expert Marc-André Verner of U de M, were published this week in Environment International.

“The blood brain barrier is not completely developed in the fetus and if exposed, those toxins may pass that barrier,” Caron-Beaudoin said. “High exposure to benzene during pregnancy is associated with low birth weight, an increased risk of childhood leukemia and birth defects.”

Benzene can’t be measured directly because it’s a volatile substance, she explained. So researchers measured the compound’s metabolites, including muconic acid, broken down by the body and released in urine. Researchers were very concerned, Caron-Beaudoin said, to discover high levels of muconic acid in the urine of the pregnant women.

The study was initially sparked by interest expressed at a Canadian symposium on toxicology, Caron-Beaudoin said.

“We had heard that some communities in Peace River Valley in northeastern British Columbia were worried about the health impacts of living near fracking,” she said. “There was no bio-monitoring (for toxic chemicals) done in this region despite it being one of the most intensive hydraulic fracking regions in the country.”

At first, the team didn’t know what to look for, Caron-Beaudoin explained.

“We couldn’t find anything similar in the literature done in Canada, so we looked in the U.S.,” she said. “We knew hydraulic fracturing may release heavy metal and volatile compounds, like benzene and toluene, so we decided to look for that in urine.”

Researchers compared their results with data from the Canadian Health Measures Survey (CHMS), a national survey that provides measures based on blood and urine samples, including environmental chemicals.

Researchers suggest the higher levels of benzene exposure in B.C. is coming from the fracking.

“But we don’t know for sure,” Caron-Beaudoin said.

Benzene is also found in cigarettes, petroleum products including motor fuels and solvents, as well as in drinking water. The study did not measure benzene in the participants’ environments, for example, in their tap water or in the air in their houses.

“The key message here is that we have a red flag,” she said. “We think there is higher benzene exposure in this region, and it’s particularly seen in the Indigenous participants, who already face social and health inequities. We need to look into this further and correct for the limitations we had in this pilot study.”

In her next study, Caron-Beaudoin expects to investigate the medical data of about 6,000 babies born in the region in the past 10 years.

The study was funded by a grant from Université de Montréal Public Health Research Institute and the West Moberly First Nations.

CORRECTION:An earlier version of this story incorrectly stated that benzene may be found in food conservation agents. In fact, the metabolites tracked in the study can come from benzene but also from food preservatives like sorbic acid. The Montreal Gazette regrets the error.

This Week's Flyers

Comments

Postmedia is pleased to bring you a new commenting experience. We are committed to maintaining a lively but civil forum for discussion and encourage all readers to share their views on our articles. Comments may take up to an hour for moderation before appearing on the site. We ask you to keep your comments relevant and respectful. Visit our Community Guidelines for more information.